fix(tool): correct git grep ref argument order in code_search

[zhuichen]

Summary

Fix code_search failures in commit/range review modes by correcting git grep argument ordering and preserving option-like ref safety checks.

Problem

In commit/range mode, code_search constructed git grep args with an invalid revision placement, which caused errors like:

• fatal: unable to resolve revision: --end-of-options

As a result, code_search became unreliable for --commit and --from/--to workflows.

Root Cause

buildGrepArgs assembled arguments in a way that made Git parse an invalid token as a revision.

Changes

• Corrected git grep arg order in:
  • internal/tool/code_search.go
• Added/kept defensive guard for option-like refs (-...) to avoid ambiguous/unsafe execution.
• Updated tests to match the corrected command structure and behavior:
  • internal/tool/code_search_test.go

Validation

Executed per contribution guide:

• go fmt ./...
• go vet ./...
• make test (race enabled)
• make build

All passed.

Impact

• Restores code_search correctness in commit/range mode.
• Improves stability of AI review tool-calls for non-workspace reviews.
• Keeps security behavior for option-like refs.

🤖 Generated with Claude Code

[CLAassistant]

All committers have signed the CLA.

[github-actions]

✅ OpenCodeReview: No comments generated. Looks good to me.

[MuoDoo]

I couldn’t reproduce the --end-of-options revision error with the current args. Could you share the exact failing case?

[guqihao-7]

I couldn’t reproduce the --end-of-options revision error with the current args. Could you share the exact failing case?我无法用当前参数复现 --end-of-options 修订版本错误。你能分享具体的失败案例吗？

I can reproduce

[guqihao-7]

I couldn’t reproduce the --end-of-options revision error with the current args. Could you share the exact failing case?

my git version is: git version 2.39.5 (Apple Git-154)

I suspect this is related to the git version. I couldn't reproduce it on my Ubuntu, but my Mac.